Fountain applicators are used for applying coating material to a web of paper for enhancing the printability of the paper.
Typically, the fountain coater or applicator applies a thin layer of liquid coating material on a moving web forcing the liquid through a slot to form a jet that is distributed on the web. To secure a uniform distribution of the liquid coating material on the web which may be 40 foot in width, it is necessary that the jet be uniform and smooth. Therefore, any mechanical parts disposed within the slot might accumulate impurities contained in the coating material thus causing an obstruction of the liquid flow subsequently damaging the uniformity of the applied layer.
The present invention provides a unique structure which permits opening the fountain applicator slot along the entire width of the slot for flushing and cleaning purposes. The unique structure utilizes a mechanical device which is disposed external relative to the distribution slot, thereby maintaining the continuity and straightness of the internal wall and slot just as is the case in the prior art type fountain applicators having fixed slots.
More particularly, the applicator according to the present invention permits opening of the thin slot for cleaning purposes both during its operation and during scheduled stops for maintenance and cleaning.
The applicator according to the present invention utilizes mechanical opening and dosing stops extending continuously along the width of the coater and disposed externally to the slot or liquid flow channel.
The system according to the present invention avoids the accumulation of dirt that could obstruct the regular flow of coating material. Also, the arrangement of the present invention maintains a repeatability of all set up working positions so that such positions are guaranteed along the entire width of the slot. Accordingly, the coater apparatus of the present invention requires little maintenance due to the simplicity of the system.
Therefore, it is a feature of the present invention to provide a coater apparatus that overcomes the problems associated with the prior art arrangements and which makes a considerable contribution to the art of manufacturing such a coater apparatus.
Another feature of the present invention is the provision of a coater apparatus which enables cleaning and flushing of the coater apparatus.
A further feature of the present invention is the provision of a coater apparatus which is simple in construction.
Another feature of the present invention is the provision of a coater apparatus which avoids the accumulation of dirt that would otherwise obstruct flow of coating material.
A further feature of the present invention is the provision of a coater apparatus which enables repeatability of all set up working positions.
Also, another feature of the present invention is the provision of a coater apparatus which maintains the continuity and straightness of the internal wall and slot.
Other features and advantages of the coating apparatus according to the present invention will be readily apparent to those skilled in the art by a consideration of the detailed description of a preferred embodiment of the invention contained herein.